Adjustable base unit for invalid lifts



p 6, 1966 G. 1. STEWART ETAL 3,270,574

ADJUSTABLE BASE UNIT FOR INVALID LIFTS Original Filed April 23, 1962 2 Sheets-Sheet 1 A Tram/A Y5 P 5, 1965 ca. 1. STEWART ETAL 3,270,574

ADJUSTABLE BASE UNIT FOR INVALID LIFTS Original Filed April 25, 1962 2 Sheets-Sheet 2 s o r*""1 ,1 n m 36 I r WI \L wf hrx/ 1 @H 21 /2 2 y 6 22 1.?

i! n ,7 I w 11 /6 i3 /y 60 /V y JNVEN TORS 645522"! haw/er United States Patent 3,270,574 ADJUSTABLE BASE UNHT FOR INVALHD LiFTS Gilbert K. Stewart and Kenneth H. Teeter, Higgins Lake, Mich; said Stewart assignor to said Teeter Continuation of application Ser. No. 189,602, Apr. 23, 1962. This application May 10, 11965, Ser. No. 454,268 2 Claims. (Cl. 74-98) This invention relates to an adjustable base unit for invalid lifts and more particularly to an adjustable base unit provided with worm gear actuated legs that are selectively movable toward and away from each other in a corresponding and symmetrical manner. This is a continuation of our co-pending application, Serial Number 189,602, now abandoned, filed April 23, 1962, entitled, Adjustable Base Unit for Invalid Lifts.

Invalid lifts have found great utility in lifting and trans ferring patients from one location to another within a room, a hospital, or a home, as required in caring for such patients. In order to provide more versatility in such invalid lifts, adjustable base legs have been provided thereon. Such adjustability was necessary so that the base legs of the lift could be spread apart to accommodate an article of furniture, such as a chair, therebetween. Such adjustability was also necessary so that the base legs could be brought close together when the invalid lift had to be moved down a narrow hall or through a narrow doorway.

However, in the devices of the prior art, it has been possible to impart only a comparatively narrow range of adjustability to the base legs. This was due to the inflexible system of linkage arms generally used to spread the base legs apart or to bring them together. In a linkage type actuating system, the are through which the base legs can be moved is necessarily limited.

Further, such linkage systems have required the use of latch or lock mechanisms so that the base legs could be held at any predetermined spaced apart position. Due to this type of structure, the base legs could be set only at predetermined positions in accordance with the type of latch control incorporated thereon. At any rate, the base legs could not be positively adjusted to and held in any desired spread apart position without the use of a latch control mechanism.

In addition, the adjustments described above had to be accomplished by use of the operator's ands. This proved to be extremely difiicult and dange s in the event that an adjustment of the base legs had to be made while a patient was being transferred to or from the lift or while he was being moved thereon.

The result has been that the adjustable base invalid lift structures of the prior known art have been complicated and expensive to fabricate and yet have not provided the desired utility and flexibility in use.

It is therefore, an object of this invention to provide an adjustable base unit for invalid lifts which does not utilize complicated linkages to bring about selective movement of the base legs toward and away from each other.

Another object of this invention is to provide an adjustable base unit for invalid lifts which does not require an associated latch or look structure to maintain the base legs in any desired spread apart use position.

Still another object of this invention is to provide an adjustable base unit for invalid lifts which imparts a wide range of selective arcuate movement of the support legs toward and away from each other.

Yet another object of this invention is to provide an adjustable base unit for invalid lifts which permits positive adjustment of the base support legs to any desired angular setting without being limited to any pre-determined structural station positions.

3,270,574 Patented Sept. 6, 1966 A still further object of this invention is to provide an adjustable base unit for invalid lifts which utilizes a positive worm gear drive assembly to selectively accomplish corresponding and symmetrical movement of the support legs toward and away from each other.

Another object of this invention is to provide an adjustable base lift which can be quickly and easily dismantled for transfer from one use location to another.

Yet another object of this invention has been to provide a foot-actuatable adjustable base unit for invalid lifts.

Another object of this invention is to provide an adjustable base unit for lifts which can be easily and economically fabricated and which requires little or no maintenance in use.

In the drawings:

FIGURE 1 is a side elevation view of the adjustable base unit illustrating in phantom line a hydraulic invalid lift assembly in position thereon and showing the foot actuator pedal wheel provided on the adjustable [base unit.

FIGURE 2 is a top view of the adjustable base unit with the invalid lift removed and showing in phantom line a representative position to which the support legs of the adjustable base unit can be selectively expanded by actuation of the pedal wheel.

FIGURE 3 is a front elevation view of the adjustable base unit frame illustrating the Worm gear actuated leg assemblies pivotally mounted thereon.

FIGURE 4 is a rear elevation view of the adjustable base unit illustrating the foot pedal structure which can be actuated to selectively cause movement of the pivotally mounted base legs toward and away from each other.

FIGURE 5 is a partial sectional view of the adjustable base unit, taken on line V-V of FIGURE 4, illustrating the foot pedal actuated worm gear structure in association with the pivotally mounted leg assemblies and showing in phantom line a representative position to which the base legs can be expanded.

General description In general, an adjustable base unit assembly is provided for use with invalid lift assemblies. An adjustable base unit frame is provided with pivotally mounted horizontally extending base support legs that are selectively a-ctuatable toward and away from each other as desired. This selective movement is made possible by the use of a worm gear drive assembly which engages the pivotally mounted base legs. The positive nature of the worm gear drive permits the elimination of latch or lock assemblies that have heretofore been necessary to retain the base support legs in any desired spread apart position.

The worm gear drive is actuatable through the use of a foot control pedal wheel in association therewith. The provision of the foot control pedal wheel greatly increases the utility and versatility of the adjustable base unit. The operator can thus make any desired changes in the positioning of the base support legs without having to take his hands from the patient or from any activity concerning the welfare of the patient.

The adjustable base uni-t and base support legs are provided with casters which permit movement of the invalid lift and adjustable base unit as desired.

Although the adjustable base unit is described herein in association with an invalid lift, it is also readily utilizable with hoists or lifts of any type.

As will be hereinafter described, a highly versatile adjustable base unit assembly is provided which has movement imparting means thereon for accomplishing corresponding and symmetrical movement of the base legs toward and away from each other through a wider arcuate range than heretofor possible.

Specific description More specifically, the embodiment of the invention as shown in the drawings consists of an adjustable base unit frame 11 having a pair of pivotally mounted horizontal outrigger legs 12 and 13 extending outwardly therefrom. In order to provide greater ease in dismantling the adjustable base support assembly for transport purposes the legs 12 and 13 are detachably connected to their pivotal connections provided on the adjustable base unit 11. However, it is within the scope of the invention to integrally provide the legs with such pivotal connections.

The legs 12 and 13 are tubular and are provided with casters 14. The legs 12 and 13 are oppositely curved at one end thereof so that when they are mounted on the adjustable base unit frame 11, they extend therefrom so as to form an overall symmetrical adjustable base assembly. This configuration is shown in FIG- URE 2.

The adjustable base unit frame 11 comprises an upper housing plate 15 and a lower housing plate 16 which are spaced apart so as :to retain the entire actuating assembly therebetween. The plates 15 and 16 are co-extensive and are substantially diamond-shaped. However, the shape of the plates is not critical so long as a suitable frame structure is provided for pivotal mounting of the legs 12 and 13 and for mounting of the worm gear actuating assembly thereon. A pair of oppositely positioned spaced apart hollow post members 17 and 18, are pivotally mounted intermediate the upper plate 15 and the lower plate 16. This is accomplished by use of bolts 19 which engage the upper surface of the upper plate 15 and pass downwardly through the upper plate 15, the hollow post members 17 and 18 and the lower plate 16 to be retentively engaged by nuts 20.

Each of the hollow post members 17 and 18,. ar provided with horizontally extending tubular portions 21 and 22, which are configured to matingly and lockably receive the ends of the legs 12 and 13, therein. Lock bolts 23 and 24, are utilized to retain the end portions of the legs 12 and 13 in their use position within the tubular extensions, 21 and 22. Holes are provided through the tubular extensions 21 and 22, and the legs 12 and 13, respectively. These holes are in register with each other when the legs are in their proper use positions within the tubular extensions 21 and 22. The lock bolts 23 and 24, can be easily dropped therethrough to lock the legs 12 and 13, within the tubular portions 21 and 22. Thus, the legs 12 and 13, can be easily dismantled from the adjustable base unit assembly by merely removing the lock bolts 23 and 24, from the aforementioned holes.

Gear wheel segment arms 25 and 26, are lockably mounted on the hollow post members 17 and 18, as shown generally in the drawings and specifically in the cross-sectional view of FIGURE 5 The gear wheel segment arms 25 and 26, extend toward each other to engage a centrally and transversely positioned worm 29 mounted on shaft 30. The shaft 30 is journalled in downwardly depending journal supports 31 and 32,

mounted on and depending from the bottom surface of the upper plate 15.

The shaft 30 extends rearwardly through and is partially supported by the rear hollow spacer support post 33. A caster 14 is provided beneath the frame unit 11 which cooperates with the casters 14 provided on the legs 12 and 13, so as to support the adjustable base assembly above a floor surface. A foot control pedal wheel 34 is lockably attached to the shaft 30 by use of a foot pedal wheel set screw 35. The foot control pedal wheel 34 is provided with a plurality of radially extending vanes 36 which greatly facilitate the actuation of the pedal wheel 34 by the foot of the operator as shown in FIGURE 1.

It is thus seen that :the pedal wheel 34 can be selectively actuated so as to cause the worm 29 to revolve clockwise or counterclockwise, as desired. The worm 29 simultaneously acts upon both of the gear wheel segment arms 25 and 26, causing them to rotate in corresponding and symmetrical opposite directions as indicated by the phantom line representations of FIGURE 2 and FIGURE 5.

Such rotation of the gear wheel segment arms 25 and 26, causes the post members 17 and 18, to pivot so as to cause the tubular extensions thereof 21 and 22, to selectively swing outwardly. This movement causes the legs 12 and 13, to arcuately spread apart from a narrow spaced apart position to a full spread apart position or to any desired intermediate position as shown by the phantom line representations of FIGURES 2 and 5.

Actuation of the worm 29 in the opposite direction will cause pivotal movement of the post members 17 and 18, in such a manner that the tubular extensions thereof will swing inwardly. This causes the legs 12 and 13, to move toward each other to a narrow spaced apart position.

It should be noted that due to the positive nature of the worm gear drive, the legs 12 and 13, do not move from any given position unless the pedal wheel 34 is actuated. This incorporates an added safety feature into the unit.

It is considered to be within the scope of the invention to vary the arcuate size of the gear wheel segment arms 25 and 26, so as to increase or decrease the distance through which the support legs can be moved. In fact, the gear wheel segment arms can be replaced by complete worm gear wheels, if a greater range of leg movement is desired.

It is to be considered as being within the scope of the invention to incorporate each base leg 12 and 13, each tubular extension 21 and 22, each hollow member 17 and 18, and each gear wheel segment arm 25 and 26, into two complementary integrally formed unitary pivotally mounted leg support assemblies that are actuated by the worm 29.

A vertical mast stub connector 37 is mountable through co-axial stub connector holes 38 provided through the forward portions of the upper plate 15 and the lower plate 16. As shown in phantom line in FIGURE 1, a lift or hoist assembly 39 can then be mounted directly on the adjustable base unit assembly. The lift assembly 39 would consist of a vertical mast 40 and a pivotally mounted arm 41 attached thereto.

A hydraulic jack assembly 42 is operatively mounted on the mast 40 so as to selectively move the arm 41 through a vertical plane. A patient carrier assembly 43 of any desired type well known in the art is provided at the free end of the arm 41. The lift or hoist assembly set forth in phantom line is believed to be well known in the art and is not intended to be part of the claimed adjustable base unit invention of the applicants.

It is thus seen that a highly versatile adjustable base unit assembly for lifts is provided which is easy to operate and which is greatly simplified structurally in that all linkages and latch lock mechanisms are eliminated.

Various modifications of the invention may be made without departing from the principle thereof. Each of these modifications is to be considered as included in the hereinafter appended claims unless these claims by their language expressly provide otherwise.

Having thus set forth the nature of our invention, we claim the following:

1. In an adjustable base unit for invalid lifts, the combination comprising:

(a) a base unit frame for invalid lifts;

(b) a pair of spaced-apart post pivot members provided on said base unit frame, each of said post pivot members provided with a gear segment arm extending therefrom, said gear segment arms spaced apart from but extending toward each other;

(c) an outrigger leg support member mounted on each of said post pivot members for selective pivotal movement toward and away from each other, each of said outrigger leg support members extending from said post pivot member away from said gear segment arms;

(d) Worm gear assembly actuating means positioned on said frame intermediate said gear segment arms and in operative engagement therewith for selectively accomplishing corresponding and symmetrical pivotal movement of said leg support members toward and away from each other; and

(e) a vertical mast stub connector provided on said base unit frame, said stub connector adapted to supportingly engage an invalid lift assembly.

2. In an adjustable base unit for invalid lifts, the combination comprising:

(a) a base unit frame for invalid lifts;

(b) a pair of spaced-apart post pivot members provided on said base unit frame, each of said post pivot members provided with a gear segment arm extending therefrom, said gear segment arms spaced apart from but extending toward each other;

() an outrigger leg support member mounted on each of said post pivot members for selective pivotal movement toward and away from each other, each of said outrigger leg support members extending from said post pivot member away from said gear segment arms;

(d) worm gear assembly actuating means positioned on said frame intermediate said gear segment arms and in operative engagement therewith for selectively accomplishing corresponding and symmetrical pivotal movement of said leg support members toward and away from each other;

(e) a vertical mast stub connector provided on said base unit frame, said stub connector adapted to supportingly engage an invalid lift assembly; and

(f) a pedal wheel member provided on said worm 0 gear assembly actuating means for selective foot actuation of said worm gear assembly actuating means.

References Cited by the Examiner UNITED STATES PATENTS 1,961,119 5/1934 Ettinger 5--86 X 2,157,263 5/1939 Johnson 7479 X 2,466,289 4/1949 Welch 586 2,701,656 2/1955 French 7498 X 2,821,406 1/1958 Hoyer et al. 5-87 X 2,869,614 1/1959 Wamsely 5-86 X 2,903,238 9/1959 Flandrick 5-86 X 2,914,110 11/1959 Schulte 581 X FOREIGN PATENTS 835,102 5/1960 Great Britain.

MILTON KAUFMAN, Primary Examiner.

BROUGHTON G. DURHAM, Examiner. D. H. THIEL, Assistant Examiner. 

1. IN AN ADJUSTABLE BASE UNIT FOR INVALID LIFTS, THE COMBINATION COMPRISING: (A) A BASE UNIT FRAME FOR INVALID LIFTS; (B) A PAIR OF SPACED-APART POST PIVOT MEMBERS PROVIDED ON SAID BASE UNIT FRAME, EACH OF SAID POST PIVOT MEMBERS PROVIDED WITH A GEAR SEGMENT ARM EXTENDING THEREFROM, SAID GEAR SEGMENT ARMS SPACED APART FROM BUT EXTENDING TOWARD EACH OTHER; (C) AN OUTRIGGER LEG SUPPORT MEMBER MOUNTED ON EACH OF SAID POST PIVOT MEMBERS FOR SELECTIVE PIVOTAL MOVEMENT TOWARD AND AWAY FROM EACH OTHER, EACH OF SAID OUTRIGGER LEG SUPPORT MEMBERS EXTENDING FROM SAID POST PIVOT MEMBER AWAY FROM SAID GEAR SEGMENT ARMS; 